Copeland, Jr., U.S. Pat. No. 3,593,647, issued Jul. 20, 1971, discloses a cooking device having a gas burner supported in a tubular container. A removable cooking grate has a peripheral rim for resting on an in-turned bead of the container, above the burner, for supporting a pot. Alternatively, a conical plate can be mounted above the burner for radiating heat more uniformly to a top grill rack. Consequently, the cooking device can be used either as a stove whereby a cooking utensil supported on the grate is heated directly by the burner or, with the conical plate inserted, as a barbecue for grilling food supported on the top rack.
Pepin U.S. Pat. No. 3,802,413, issued Apr. 9, 1974, discloses a camp stove having a burner in a bottom drawer. With the drawer closed, the burner can be used to light charcoal for barbecuing, or the drawer can be opened to expose the burner for heating a cooking utensil.
Panzarella U.S. Pat. No. 4,062,341, issued Dec. 13, 1977, discloses a portable cooking device having an internal burner and a top rim designed for supporting a wok. Alternatively, a grill rack can be supported on the top of the device for supporting other types of cooking utensils.
Hahn U.S. Pat. No. 4,446,846, issued May 8, 1984, discloses a gas cooking device having side-by-side "fire grate modules" such that one module can be inserted for barbecuing while the other side is used for heating a pot or a pan.
Kazuo et al. U.S. Pat. No. 4,603,684, issued Aug. 5, 1986, discloses a gas cooking device having an annular "holder" above a burner. Different utensil supports or grates can be mounted in the holder for different cooking operations.
Yamada U.S. Pat. No. 4, 877,015, issued Oct. 31, 1989, discloses a cooking device similar to the Kazuo et al. device in that different types of supports (i.e., a grill rack or a pot stand) can be mounted above a burner.
Boetcker U.S. Pat. No. 4,909,235, issued Mar. 20, 1990, discloses another cooking device having an annular support for different types of cooking utensils and a removable top grill rack.
O'Quin U.S. Pat. No. 4,944,284, issued Jul. 31, 1990, discloses yet another cooking device having an internal support for a pot or pan (see FIGS. 4 and 5) and a removable upper rack for grilling.
The devices of the patents discussed above are representative of prior efforts to provide a portable cooker usable for different cooking operations, but there still exists a need for a sturdy, compact cooker which is easy to use and is effective for heating standard cooking utensils and also for barbecuing or grilling.